Re: C-x 4 a ceased to work in *cvs-diff* buffer

[Stefan <monnier@iro.umontreal.ca>]

>> I can't reproduce this here.  Could you give some more info?

> Perhaps two hours ago I updated my working copy, and it still
> happens.  I proceeded as follows:
[...]
> And here is the *cvs-diff* buffer for tramp.el:

>     pcl-cvs: descending directory lisp/net/
>     Index: tramp.el
>     ===================================================================
>     RCS file: /cvsroot/emacs/emacs/lisp/net/tramp.el,v
>     retrieving revision 1.50
>     diff -u -r1.50 tramp.el
>     --- tramp.el	10 Aug 2004 20:49:45 -0000	1.50
>     +++ tramp.el	10 Oct 2004 11:57:11 -0000

Hmm... it seems pcl-cvs decided to run `cvs diff' in `single-dir' mode
(i.e. one invocation per directory).  So presumably `cvs-execute-single-dir'
is set to t.  Could you check why that is?  It's probably because
`cvs-version' is not initialized to a proper value.

The other problem is that diff-mode does not take advantage of the
annotation `pcl-cvs: descending directory lisp/net/': the code is simply
missing (the annotation is currently only used by pcl-cvs itself and by
cvs-status.el).

Could you try the patch below that tweaks diff-mode to pay attention to the
pcl-cvs annotation?


        Stefan


--- orig/lisp/diff-mode.el
+++ mod/lisp/diff-mode.el
@@ -1,6 +1,7 @@
 ;;; diff-mode.el --- a mode for viewing/editing context diffs
 
-;; Copyright (C) 1998,1999,2000,01,02,03,2004  Free Software Foundation, Inc.
+;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004
+;;           Free Software Foundation, Inc.
 
 ;; Author: Stefan Monnier <monnier@cs.yale.edu>
 ;; Keywords: convenience patch diff
@@ -517,14 +518,16 @@
 	       (list (if old (match-string 2) (match-string 4))
 		     (if old (match-string 4) (match-string 2)))))))))
 
-(defun diff-find-file-name (&optional old)
+(defun diff-find-file-name (&optional old prefix)
   "Return the file corresponding to the current patch.
-Non-nil OLD means that we want the old file."
+Non-nil OLD means that we want the old file.
+PREFIX is only used internally: don't use it."
   (save-excursion
     (unless (looking-at diff-file-header-re)
       (or (ignore-errors (diff-beginning-of-file))
 	  (re-search-forward diff-file-header-re nil t)))
     (let ((fs (diff-hunk-file-names old)))
+      (if prefix (setq fs (mapcar (lambda (f) (concat prefix f)) fs)))
       (or
        ;; use any previously used preference
        (cdr (assoc fs diff-remembered-files-alist))
@@ -546,6 +549,13 @@
        (and (string-match "\\.rej\\'" (or buffer-file-name ""))
 	    (let ((file (substring buffer-file-name 0 (match-beginning 0))))
 	      (when (file-exists-p file) file)))
+       ;; If we haven't found the file, maybe it's because we haven't paid
+       ;; attention to the PCL-CVS hint.
+       (and (not prefix)
+	    (boundp 'cvs-pcl-cvs-dirchange-re)
+	    (save-excursion
+	      (re-search-backward cvs-pcl-cvs-dirchange-re nil t))
+	    (diff-find-file-name old (match-string 1)))
        ;; if all else fails, ask the user
        (let ((file (read-file-name (format "Use file %s: " (or (first fs) ""))
 				   nil (first fs) t (first fs))))
@@ -1422,5 +1432,5 @@
 ;; use `combine-after-change-calls' to minimize the slowdown of font-lock.
 ;;
 
-;;; arch-tag: 2571d7ff-bc28-4cf9-8585-42e21890be66
+;; arch-tag: 2571d7ff-bc28-4cf9-8585-42e21890be66
 ;;; diff-mode.el ends here